New START replaced the Treaty of Moscow (SORT), which was due to expire in December 2012. In terms of name, it is a follow-up to the START I treaty, which expired in December 2009, the proposed START II treaty, which never entered into force, and the START III treaty, for which negotiations were never concluded.

Under terms of the treaty, the number of strategic nuclear missile launchers will be reduced by half. A new inspection and verification regime will be established, replacing the SORT mechanism. It does not limit the number of operationally inactive stockpiled nuclear warheads that remain in the high thousands in both the Russian and American inventories.[7]

Under the terms of the treaty, the number of strategic nuclear missile launchers will be reduced by half. The treaty limits the number of deployed strategic nuclear warheads to 1,550, which is down nearly two-thirds from the original START treaty, as well as 10% lower than the deployed strategic warhead limit of the 2002 Moscow Treaty.[8] The total number of deployed warheads, however, could exceed the 1,550 limit by a few hundred because per bomber only one warhead is counted regardless of how many it actually carries.[8] It will also limit the number of deployed and non-deployed inter-continental ballistic missile (ICBM) launchers, submarine-launched ballistic missile (SLBM) launchers, and heavy bombers equipped for nuclear armaments to 800. The number of deployed ICBMs, SLBMs, and heavy bombers equipped for nuclear armaments is limited to 700.[9] The treaty allows for satellite and remote monitoring, as well as 18 on-site inspections per year to verify limits.[8]

These obligations must be met within seven years from the date the treaty enters into force. The treaty will last ten years, with an option to renew it for up to five years upon agreement of both parties.[11] The treaty entered into force on 5 February 2011, when the United States and Russia exchanged instruments of ratification, following approval by the U.S. Senate and the Federal Assembly of Russia.[12] However, the United States began implementing the reductions even before the treaty was ratified.[13]

Documents made available to the U.S. Senate described[clarification needed] removal from service of at least 30 missile silos, 34 bombers and 56 submarine launch tubes, though missiles removed would not be destroyed and bombers could be converted to conventional use. While four of 24 launchers on each of the 14 ballistic missile nuclear submarines would be removed, none would be retired.[14]

The treaty places no limits on tactical systems, such as the Lockheed Martin F-35 Lightning II, which will most likely be replacing the F-15E and F-16 in the tactical nuclear delivery role.[15]

The treaty does not cover rail-mobile ICBM launchers because neither party currently possesses such systems. ICBMs on such launchers would be covered under the generic launcher limits, but the inspection details for such systems would have to be worked out between the parties if such systems were reintroduced in the future.[16]

The New START treaty is the successor to the START I. The START II was signed, but not ratified. The START III negotiating process was not successful.

The drafting of the treaty commenced in April 2009 immediately after the meeting between the presidents of the two countries, Barack Obama and Dmitry Medvedev, in London.[17] Preliminary talks were already held in Rome on 27 April,[18] although it was originally planned to have them held in the middle of May.[19]

On the morning of 6 July, the agreement on the text of the "Joint Understanding on Further Reduction and Limitation of Strategic Offensive Arms" was announced,[28][29] which was signed by Medvedev and Obama during the US Presidential visit to Moscow the same day. The document listed the intention of both parties to reduce the number of nuclear warheads to 1,500 – 1,675 units, as well as their delivery weapons to 500 – 1,100 units.[30]

Presidents Obama and Medvedev announced on 26 March 2010 that they had reached an agreement, and they signed the treaty on 8 April 2010 in Prague.[3]

On 13 May, the agreement was submitted by U.S. President Barack Obama for ratification in the U.S. Senate. Ratification required 67 votes in favor (out of 100 Senators). On Tuesday, 16 September 2010 the Senate Foreign Relations Committee voted 14–4 in favor of ratifying New START. The measure had support from three Senate Republicans: Richard Lugarof Indiana, Bob Corker of Tennessee, and Johnny Isakson of Georgia.[31] Senator John Kerry[32] and Secretary of State Hillary Clinton expressed optimism that a deal on ratification was near.[33]

Republicans in the Senate generally deferred to Jon Kyl (R-AZ), a leading conservative on defense issues, who sought a strong commitment to modernize U.S. nuclear forces, and questioned whether there was time for ratification during the lame duck session, calling for an opening of the negotiation record before a vote is held.[34] Senator Ben Nelson (D-NE) joined Kyl in expressing skepticism over the timing of ratification,[35] and Senator Kit Bond (R-MO) expressed opposition.[36]

Obama made New START ratification a priority during the 2010 post-election lame duck session of Congress, and Senators John Kerry (D-MA) and Richard Lugar (R-IN), the Democratic Chairman and senior Republican on the Senate Foreign Relations Committee, were leading supporters of the treaty.[37][38][39]

On 22 December 2010, the U.S. Senate gave its advice and consent to ratification of the treaty, by a vote of 71 to 26 on the resolution of ratification.[40] Thirteen Republican senators, all 56 Democratic senators, and both Independent senators voted for the treaty.[41] President Obama signed documents completing the U.S. ratification process on 2 February 2011.[42]

On 28 May 2010, the document was introduced by Medvedev for consideration in the State Duma. On 6 July, the State Duma held parliamentary hearings on the treaty, which was attended by representatives from the Foreign Ministry and General Staff. On 8 July, the Duma Defense Committee and the International Affairs Committee recommended that the State Duma ratify the treaty.

However, on 29 October, the chairman of the Duma International Affairs Committee, Konstantin Kosachev, called for the return of the document to committee hearings, noting that the agreement does not restrict the activities of the United States on missile defense, as well as the fact that ballistic missiles with non-nuclear warheads are not covered under the agreement. At the same time, Federation Council Chairman Sergei Mironov proposed not to rush to the amendment, or vote on the treaty, and to monitor the discussions in the U.S. Senate.

Following ratification by the U.S. Senate, the formal first reading of the treaty was held on 24 December and the State Duma voted its approval. The State Duma approved a second reading of the treaty on 14 January 2011.[43] 349 deputies out of 450 voted in favor of ratification.

The third and final reading by the State Duma took place on 25 January 2011 and the ratification resolution was approved by a vote of 350 deputies in favor, 96 against, and one abstention.[44] It was then approved unanimously by the Federation Council on the next day.[5][45]

On 28 January 2011, Medvedev signed the ratification resolution passed by the Federal Assembly, completing the Russian ratification process.[6] The treaty went into force when Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State Hillary Clinton exchanged the instruments of ratification at the Security Conference in Munich, Germany, on 5 February 2011.[1][5][6]

The New START Treaty requires a number of specific actions within periods after Entry into Force (EIF) (5 February 2011)[46]

No later than (NLT) 5 days after EIF

Exchange Inspection Airplane Information:

Lists of the types of airplanes intended to transport inspectors to points of entry will be exchanged.

NLT 25 days after EIF

Exchange Lists of Inspectors and Aircrew Members:

Lists of initial inspectors and aircrew will be exchanged.

NLT 45 days after EIF

Exchange databases:

Databases will provide information on the numbers, locations, and technical characteristics of weapon systems and facilities that are covered under the Treaty.

NLT 60 days after EIF

Exhibition: Strategic Offensive Arms:

If a type, variant, or version of a strategic offensive arm (SOA) that was not exhibited in connection with the START Treaty is declared, then the SOA's features and technical characteristics must be demonstrated and confirmed.

60 days after EIF

Right to Conduct Inspections Begins:

Parties may begin inspections, 18 on-site inspections per year are provided in the Treaty. Each Party is allowed ten Type One Inspections and eight Type Two Inspections.

Type One Inspections focus on deployed and non-deployed SOAs sites. Activities include confirming accuracy of data on SOAs, the number of warheads located on designated deployed ICBMs and SLBMs, and the number of nuclear armaments to be on designated deployed heavy bombers.

Type Two Inspections focus on sites with non-deployed SOAs. They can involve confirmation of the conversion/elimination of SOAs, and confirming the elimination of facilities.

NLT 120 days after EIF

Exhibition: Heavy Bombers at Davis-Monthan Air Force Base:

The United States will conduct a one-time exhibition of each type of environmentally-sealed deployed heavy bombers located at the storage facility at Davis-Monthan Air Force Base in Arizona.

NLT 180 days after EIF

Initial Demonstration of Telemetry Playback Equipment:

Parties will conduct an initial demonstration of recording media and playback equipment for telemetric information, information that originates on a missile during its initial motion and flight.

NLT 225 days after EIF

Exchange Updated Databases:

Parties will exchange updated databases and every six months thereafter for the duration of the Treaty.

NLT 1 year after EIF

Exhibition: B-1B Heavy Bomber:

The United States will conduct a one-time exhibition of a B-1B heavy bomber equipped with non-nuclear armaments to demonstrate it no longer can employ nuclear armaments.

NLT 3 years after EIF

Exhibition: Previously Converted Missile Launchers:

The United States will conduct a one-time exhibition of its four SSGNs, which are equipped with cruise missile launchers and were converted from nuclear ballistic submarines, to confirm that SSGNs cannot launch SLBMs. The United States will also hold an exhibition of the five converted ICBM launcher silos at Vandenberg Air Force Base in California, now used as missile defense interceptor launchers. This will confirm that the converted launchers are no longer able to launch ICBMs and determine the features to distinguish converted silo launchers from unconverted ones.

NLT 7 years after EIF

Meet Central Treaty Limits:

Parties are required to meet the limits laid out in the Treaty for deployed strategic warheads, and deployed and non-deployed strategic delivery vehicles and launchers.

In the United States, a debate about whether to ratify the treaty took place during the lead-up to the 2010 midterm elections and in the lame-duck congressional session afterward. While one public opinion poll showed broad support for ratification,[47] another showed general skepticism over nuclear arms reductions.[48][49][unreliable source?]

Obama administration officials discussing the New START Treaty at a meeting.

Republican supporters included former President George H. W. Bush[53] and all six former Republican Secretaries of State, who wrote supportive op-eds in the Washington Post[54] and the Wall Street Journal.[55] Conservative columnist Robert Kagan, who supported the treaty, says its goals are actually modest compared to previous START treaties and that the treaty should not fail because of partisan disagreements. Kagan said the Republican insistence on upgrading the U.S. nuclear arsenal was reasonable but would not be affected by the current language of the treaty.[56]

The Heritage Action for America advocacy group, an affiliate of the Heritage Foundation, took the lead in opposing New START, lobbying the Senate along with running a petition drive and airing political advertisements before November's midterm elections. The effort drew the support of likely presidential candidate Mitt Romney, and has been credited by former Senate Majority Leader Tom Daschle as changing some Republican votes.[57] According to Heritage Foundation President Ed Feulner, the language of the New START treaty would "definitely" reduce America's nuclear weapon capacity but "wouldn't necessarily" reduce Russia's, and Russia would maintain a 10–1 advantage in tactical nuclear weapons, which are not counted in the treaty.[58]

Arms control experts critical of the treaty included Robert Joseph, former undersecretary of state for arms control and international security, and Eric Edelman, undersecretary of defense for policy, who have written that the treaty weakens U.S. defenses.[59] Former CIA Director James Woolsey also said that "concessions to Russian demands make it difficult to support Senate approval of the new treaty".[60]

Senators Jon Kyl and Mitch McConnell complained about a lack of funding for the Next-Generation Bomber during the treaty debate even though this platform would not be constrained by this treaty.[61][62] During the Senatorial debate over the US ratification of the New START Treaty with Russia, Senator James Inhofe (R-OK) stated that "Russia cheats in every arms control treaty we have with them", which caused an uproar in Russian media.[63] Additionally, there were concerns about the possibility of restrictions being imposed on the deployment of missile defense systems by the U.S.[64][65]

The Pentagon's "Report on the Strategic Nuclear Forces of the Russian Federation Pursuant to Section 1240 of the National Defense Authorization Act for Fiscal Year 2012" found that even if Russia did cheat and achieved a total surprise attack with a breakout force, it would have "little to no effect" on U.S. nuclear retaliatory capabilities.[66]

Current information on the aggregate numbers and locations of nuclear weapons have been made public under the New START treaty,[67] and on 13 May 2011 three former U.S. officials and two non-proliferation experts signed an open letter to both sides asking that the information be released, in order to promote transparency, reduce mistrust, and support the nuclear arms control process in other states.[68]